Chapter 7, Problem 68P

A 10-kg box is pulled along P,Na rough surface by a force P, as shown in thefigure. The pulling force linearly increaseswith time, while the particle is motionless att = 0s untilit reaches a maximum force of100 Nattimet = 4s. If the ground has staticand kinetic friction coefficients of u, = 0.6 andHU, = 0.4 respectively, determine the velocityof the A 1 0 - kg box is pulled along P , N a rough surface by a force P , as shown in the figure. The pulling force linearly increases with time, while the particle is motionless at t = 0 s untilit reaches a maximum force of 1 0 0 Nattimet = 4 s . If the ground has static and kinetic friction coefficients of u , = 0 . 6 and HU , = 0 . 4 respectively, determine the velocity of the particle att = 4 s .

Calculate the speed of the driven member with the following conditions: Diameter of the motor pulley: 4 in Diameter of the driven pulley: 12 in Speed of the motor pulley: 1800 rpm

4. In the figure, shaft A made of AISI 1010 hot-rolled steel, is welded to a fixed support and is subjected to loading by equal and opposite Forces F via shaft B. Stress concentration factors K₁ (1.7) and Kts (1.6) are induced by the 3mm fillet. Notch sensitivities are q₁=0.9 and qts=1. The length of shaft A from the fixed support to the connection at shaft B is 1m. The load F cycles from 0.5 to 2kN and a static load P is 100N. For shaft A, find the factor of safety (for infinite life) using the modified Goodman fatigue failure criterion. 3 mm fillet Shaft A 20 mm 25 mm Shaft B 25 mm